Illuminated surgical retractor

ABSTRACT

A surgical retractor, comprising a blade having a top surface and a bottom surface, and a handle extending at an angle from a proximal end of the blade, wherein the blade and the handle are molded from a glass-fiber reinforced polymer having a flexural strength of at least 300 Mpa, and wherein the blade, being molded from the glass-fiber reinforced polymer, deforms less than 10 mm under 15 lbs of force applied thereto.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/178,675 filed on Jun. 10, 2016, which is a continuation-in-part ofU.S. patent application Ser. No. 14/614,413, filed on Feb. 5, 2015, andentitled “Illuminated Surgical Retractor.” The entire contents of bothpriority applications are incorporated herein by reference.

INTRODUCTION

Existing technology for illumination during surgical/medical proceduresincludes overhead illumination. This illumination comes from eitheroverhead lighting or head mounted fiber optic systems. Traditionaloverhead lighting systems face numerous limitations. A direct exposureof the field from the overhead source is required. Changes in patient orsurgeon positioning may interfere with the light source. Frequentadjustments provide an inconvenience for the surgeon and disrupt thesurgical flow. Overhead lighting is frequently inadequate for surgery indeeper cavities where more intense focused illumination may be required.

In addition, the alignment of the surgeon's head frequently interfereswith the remote illumination and prevents light from reaching the field.Head mounted fiber optic systems are used frequently for more limitedsurgical exposures. However, these devices have numerous limitations.

First, the surgeon is tethered by the light cord attached to theheadset, limiting the mobility in the operating room.

Second, the devices are associated with head and neck fatigue withfrequent or prolonged use.

Third, the devices require the surgeon to maintain a steady head andneck position to provide a constant and steady illumination of thefield.

Fourth, the use of remote light sources and fiber bundles introducestremendous inefficiencies into the system. A typical ten-foot long cablewill lose illumination by approximately 10% per foot of cable for a300-watt light source, which results in much lower illumination thandesired.

Fifth, a head lamp's illumination is not collinear with the doctor'seyes, and may cast shadows in the field of view when illuminatingsurgical cavities.

Sixth, halogen bulbs get very hot and often burn the skin surroundingthe surgical pocket the surgeon is working in.

Other existing technology for illumination during surgical/medicalprocedures includes lighted surgical retractors. These retractorsinclude integral or attached light sources which project light locallydown the retractor blade. Existing lighted surgical retractors overcomethe problems with overhead illumination, but still suffer from severalshortcomings. These retractors can generally be classified into twocategories.

The first category includes those with detachable light sources. Thiscategory allows the retractor to be re-used and therefore the retractormust be sterilized prior to re-use. Characteristics of most lightsources are not compatible with many sterilization procedures. Forexample, it is uncommon for batteries to carry out high temperaturesterilization. It is also difficult to completely remove organicmaterial from light source assemblies.

To overcome these difficulties, lighted surgical retractors withdetachable light sources were created. These light sources arereleasably attached to the retractor via tape or other adhesive orclip-on mechanism. This class of lighted surgical retractors requiresassembly prior to use and disassembly, cleaning, and sterilization afteruse. Such assembly, disassembly, cleaning, and sterilization representsignificant time, cost, and inefficiency for the user.

The second category of lighted surgical retractors consists of surgicalretractors with light sources that are integrated into the retractor andare not removable. These lighted surgical retractors contain a powersource in the retractor handle, an illumination device built into, orpermanently attached to the blade, and some form of optical orelectrical coupling between the power source and the illuminationdevice. The power source can be batteries or a device that will pluginto the wall. It could also be an optical power source that generatesoptical energy instead of electrical energy. The illumination device iseither one or more light emitting diodes, filament light bulbs, a fiberoptic cable, or an optical waveguide. The form of coupling is eitherwiring for an electrical connection, or a fiber optic cable or opticalwaveguide for optical coupling.

This second category of lighted surgical retractors eliminates theproblem of assembly and disassembly from which the first category ofsurgical retractors suffers. But this second class of retractors stillsuffers from difficulty in cleaning and sterilization.

Moreover, in order to be sterilizable (i.e., to withstand the thermaltrauma of high pressure steam sterilization), surgical retractors havebeen generally made of stainless steel. If they had any attachedlighting system this required hand disassembly after use, hand cleaningand then repackaging for gas sterilization of the lighting apparatus.This device then required reassembly on the surgical table prior to use.

Also, the known techniques involved in integrating light sourcecomponents into the handle and blade are generally costly. Recentevidence is emerging that procedures for cleaning and sterilization areoften flawed in practice, resulting in possible cross contamination ofpatients. These deficiencies have prevented a widespread adoption ofthis second category of lighted surgical retractors.

Embodiments described herein represent a new class of lighted surgicalretractors that does not suffer from these known deficiencies. Theseembodiments completely eliminate the risk of cross contamination byensuring that each retractor can be only used once. These embodimentseliminate the costly electrical or optical interconnect systems requiredby previous retractors. These embodiments also eliminate the requirementof assembly, disassembly, cleaning, and re-sterilization by the enduser.

Embodiments described herein provide an illuminated surgical retractor,which can be discarded after a single use due to its intrinsic low cost.

In one or more exemplary embodiments, an illuminated surgical retractorincludes a blade, a handle, a curved section, and an illuminationassembly. The blade has a top surface and a bottom surface. The handleextends at an angle from a proximal end of the blade. The curved sectionconnects the handle to the blade. The illumination assembly includes atleast one light source, at least one battery and an activation devicefor energizing the light source. The illumination assembly ispermanently attachable to the curved section.

In one or more embodiments, a chemical capacity of the battery issufficient for a single use.

In one or more embodiments, the illumination assembly includes a lightcase integrally molded.

In one or more embodiments, the illumination assembly includes aplurality of retaining tabs protruded from the light case. Theilluminated surgical retractor further includes a plurality ofacceptance slots and an acceptance cavity. The acceptance slots arelocated vertically, horizontally or at an angle with the curved section,and are configured for accepting the retaining tabs. The acceptancecavity is in communication with the acceptance slots. When the retainingtabs are inserted fully into the acceptance slots, the retaining tabsarrive at the acceptance cavity.

When compared with the prior art, the exemplary embodiments describedherein have at least the following advantages:

(1) The non-directional shape of the retaining tab allows theillumination assembly to be utilized with either vertically releasedmolds or horizontally released molds. This use of a common illuminationassembly for a wide variety of retractor shapes dramatically lowers thecost of the illuminated surgical retractor.

(2) The chemical capacity of the batteries is sufficient for only asingle use and the illuminated surgical retractor is discarded after thesingle use. The intrinsic low cost of these embodiments makes theilluminated surgical retractor economically attractive, and eliminatesthe inefficiency and expense of cleaning and re-sterilization.

(3) The materials and structure enable the device to be radiolucent,allowing patient imaging devices to directly view the body cavity withthe retractor inserted.

(4) The materials and structure enable the device to beelectroresistive, allowing the physician to utilize electrocauterizingtools in the cavity while the retractor is inserted without worry ofshorting out the electrocauterizing tool.

One exemplary aspect comprises an illuminated surgical retractor,comprising: a blade having a top surface and a bottom surface; a handleextending at an angle from a proximal end of the blade; a curved sectionconnecting the handle to the blade; and an illumination assemblycomprising at least one light source, at least one battery and anactivation device for energizing the light source, and the illuminationassembly being permanently attached to the retractor; wherein the blade,handle, and curved section are molded from a glass-fiber reinforcedpolymer.

One exemplary aspect comprises an illuminated surgical retractor,comprising: a blade having a top surface and a bottom surface; a handleextending at an angle from a proximal end of the blade; a curved sectionconnecting the handle to the blade; and an illumination assemblycomprising at least one light source, at least one battery and anactivation device for energizing the light source, and the illuminationassembly being permanently attached to the retractor; wherein the blade,handle, and curved section are molded from a low conductivity polymer.

One exemplary aspect comprises an illuminated surgical retractor,comprising: a blade having a top surface and a bottom surface; a handleextending at an angle from a proximal end of the blade; a curved sectionconnecting the handle to the blade; and an illumination assemblycomprising at least one light source, at least one battery and anactivation device for energizing the light source, and the illuminationassembly being permanently attached to the curved section; wherein theblade, handle, and curved section are molded from a radiolucent polymer.

In various embodiments: (1) the polymer is a 50% glass-fiber reinforcedpolymer; (2) the polymer is a polyarylamide compound; (3) the polymer isa thermoplastic crystalline polymer; (4) the polymer is a thermoplasticcrystalline polymer of aromatic diamines and aromatic dicarboxylicanhydrides; (5) the polymer is a glass-fiber reinforced polyacrylamide;(6) the polymer is at least 50% glass-fiber reinforced; (7) the polymerhas a flexural modulus of at least 17 Gpa; (8) the polymer has aflexural strength of at least 375 Mpa; (9) the polymer has an impactstrength of at least 100 J/M; (10) the illumination assembly ispermanently attached to the curved portion; and/or (11) the polymer hasa conductivity of less than 10-6 A.

Further features and advantages will be apparent to those skilled in theart after reviewing the drawings and detailed description providedherein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of an illuminated surgical retractoraccording to an embodiment of the present disclosure.

FIG. 2 is a rear view of the illuminated surgical retractor of FIG. 1.

FIG. 3 is a side view of the illuminated surgical retractor of FIG. 1.

FIG. 4 is an exploded view of the illuminated surgical retractor of FIG.1.

FIG. 5 is a schematic view of the illumination assembly of theilluminated surgical retractor of FIG. 1.

FIG. 6 is a front view of the illumination assembly of FIG. 5.

FIG. 7 is a partially enlarged view of the illuminated surgicalretractor of FIG. 1 with the illumination assembly removed.

FIG. 8 is a partially enlarged view of the illuminated surgicalretractor of FIG. 1 with the illumination assembly removed.

FIG. 9 is a fluoroscopy image illustrating the radiolucency of anembodiment.

FIG. 10 illustrates flexural strength and flexural modulus for a varietyof plastics.

DETAILED DESCRIPTION OF SELECT EMBODIMENTS

Drawings will be used herein to describe select exemplary embodiments.For the sake of clear illustration, many practical details will beexplained together in the description below. However, it should beappreciated that the practical details should not be used to limit theclaim scope. In other words, in some embodiments, certain details arenot essential. Moreover, for the sake of drawing simplification, somecustomary structures and elements in the drawings will be schematicallyshown in a simplified way. Wherever possible, the same reference numbersare used in the drawings and the description to refer to the same orlike parts.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art. It should be further understood thatterms, such as those defined in commonly used dictionaries, should beinterpreted as having a meaning that is consistent with their meaning inthe context of the relevant art and the present description, and shouldnot be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

FIG. 1 is a schematic view of an illuminated surgical retractor 10according to an exemplary embodiment. FIG. 2 is a rear view of theilluminated surgical retractor 10 of FIG. 1. As shown in FIGS. 1-2, anilluminated surgical retractor 10 includes a blade 11, a handle 12, acurved section 16 and an illumination assembly 50. The blade 11 has atop surface 14 and a bottom surface. The handle 12 extends at an anglefrom a proximal end of the blade 11. The curved section 16 connects thehandle 12 to the blade 11. The illumination assembly 50 includes atleast one light source 64, at least one battery 62 and an activationdevice for energizing the light source 64. The illumination assembly 50is attachable to the curved section 16.

Furthermore, the blade 11 and the handle 12 are joined together at anangle through the curved section 16 to form a retractor component 15. Inpractical applications, the blade 11, the handle 12, and the curvedsection 16 are integrally molded as a single piece. In addition, in thisembodiment, the angle may be in a range of, for instance, 35 to 170degrees, and can particularly be 90 degrees. The retractor component 15may be made of any material, but preferably high strength plastic suchas ABS or polyarylamide and made by a low cost manufacturing processsuch as injection molding. The top surface 14 of the blade 11 may beconcave (or flat, or convex).

The blade 11 may have uniform width or may be shaped such that thedistal end Is wider or narrower than the proximal end. The blade 11 mayhave a lip at the end of it for retaining tissue, or may be curved asshown to prevent retention of tissue. In this embodiment, the handle 12is in a rectangular form, but in other embodiments, the handle 12 may becircular or oval in shape, and may be opened on one or more sides. Theillumination assembly 50 is integrated into the angular space connectingthe blade 11 with the handle 12. Integration into this angular spaceallows the batteries 62 and the illumination assembly 50 to reside in alight enclosure 51 and eliminates the electrical or optical couplingrequirements in previous disclosures.

FIG. 3 is a side view of the illuminated surgical retractor 10 ofFIG. 1. In this embodiment, as shown in FIG. 3, the removal of pull tab63 is used to energize the illumination assembly 50. Other embodimentsmay include the use of an electrical switch.

FIG. 4 is an exploded view of the illuminated surgical retractor 10 ofFIG. 1. The light source 64 is used to provide illumination to the areaof the blade 11 of the illuminated surgical retractor 10. The lightsource 64 can be any suitable light source, such as, for example, alight emitting diode (LED), an incandescent element, or a fluorescentelement.

In this embodiment, the light source 64 is angled so that substantiallyall of the light travels to the distal end of the blade 11. In otherembodiments, the light source 64 can be angled so as to providesubstantially all of the light above the blade 11, or at other angles tothe blade 11 that are preferable for the medical application of theilluminated surgical retractor 10.

The batteries 62 provide power to the light source 64. The batteries 62are small enough to be contained in the angled space between the blade11 and the handle 12. Examples of the batteries 62 include LR41 or AG3type button batteries. These batteries 62 are of a very low price. Inthis embodiment, three batteries 62 are used to provide power to thelight source 64. Three batteries 62 eliminate the need for expensivecircuitry to condition the voltage and current required by the lightsource 64. These batteries 62 contain sufficient energy for 20-40minutes of use, which is sufficient for the vast majority of medicalprocedures. In other embodiments, a different number and type ofbatteries 62 can be used with or without conditioning circuitry.

FIG. 5 is a schematic view of the illumination assembly 50 of theilluminated surgical retractor 10 of FIG. 1. FIG. 6 is a front view ofthe illumination assembly 50 of FIG. 5. The light case 51 contains thelight source 64, the batteries 62, a spring 51, and the pull tab 63. Thelight source 64 has electrical leads 65 and 66 which are cut to anappropriate length and bent such that the electrical lead 65 makes anelectrical contact with the anode or cathode of one battery 62 and theelectrical lead 66 makes an electrical contact with the spring 61. Inthis embodiment, the spring 61 is made of a metal such as stainlesssteel. In other embodiments, other electrically conductive materialssuitable for producing a spring may be used. The spring 61 makes anelectrical contact with the opposite battery polarity other than thatpreviously mentioned, and the spring 61 makes this contact with onebattery 62.

The spring 61 is assembled in a compressed condition such that thespring 62 applies a force to the batteries 62, the pull tab 63, and thelight source leads 65 and 66. This force ensures electrical contactbetween the batteries 62, the light source leads 65 and 66, the spring61, and the pull tab 63. The pull tab 63 is made of an electricallyinsulative material such as polymer, plastic, or film. The pull tab 63prevents an electric current from flowing to the light source 64 whilethe pull tab 63 is inserted between two of the batteries 62. The removalof the pull tab 63 will cause the spring 61 to push together thebatteries 62 and allow an electric current to flow to the light source64. Thus, light is emitted from the light source 64. The application ofthe pull tab 63 is a very low cost method to control the energizing ofthe electrical circuit. In other embodiments, a switch may be utilizedinstead of the pull tab 63 to complete the circuit of the batteries 62and the light source 64. One having ordinary skill in the art willunderstand these other embodiments.

As shown in FIGS. 5-6, the illumination assembly 50 includes a lightcase 51. Retaining tabs 52 protrude from the light case 51. The lightcase 51 is integrally molded and in this embodiment is made of amoldable material such as plastic or nylon, although in otherembodiments other materials may be used. Moreover, the illuminationassembly 50 includes a plurality of retaining tabs 52. To be morespecific, the retaining tabs 52 are located at the distal end of thelegs 53, and are protruded at right angles to the legs 53. In thisembodiment, the retaining tabs 52 are initially compressed when insertedinto acceptance slots 71 (not shown in FIGS. 5-6).

FIGS. 7-8 are partially enlarged views of the illuminated surgicalretractor 10 of FIG. 1 with the illumination assembly 50 removed. Asshown in FIGS. 7-8, the illuminated surgical retractor 10 furtherincludes a plurality of acceptance slots 71 and an acceptance cavity 72.The acceptance slots 71 are located vertically, horizontally, or at anangle with the curved section 16, and are configured for accepting theretaining tabs 52. The acceptance slots 71 are in communication with theacceptance cavity 72 (shown in FIG. 8). When the retaining tabs 52 areinserted fully into the acceptance slots 71, the retaining tabs 52arrive at the acceptance cavity 72. The acceptance cavity 72 is arrangedto remove compression on the retaining tabs 52 and will inhibit theremoval of the retaining tab 52 from the acceptance cavity 72. In thisembodiment, the acceptance cavity 72 is recessed into the retractorcomponent 15 such that the retaining tabs 52 will not protrude from thesurface of retractor component 15. The lack of any protrusion allows fora smooth surface of the blade 11 and the handle 12, and an angled areabetween the blade 11 and the handle 12 prevents tissue irritation duringmedical procedures.

The retaining tabs 52, the retaining legs 53, the acceptance slots 71,and the acceptance cavity 72 allow novel flexibility in the creation ofinjection molds for the retractor component 15. In this embodiment, theinjections slots are vertical, as required for molds that are designedto be released vertically. One having ordinary skill in the art ofinjection molding will recognize that the shape of the retractorcomponent 15 requires molds that release vertically.

Other embodiments of the retractor component 15 may contain shapes thatrequire horizontal mold releases and thus will have horizontalacceptance slots and cavities. The non-directional shape of theretaining tab 52 allows the illumination assembly 50 to be utilized witheither vertically released molds or horizontally released molds. The useof a common illumination assembly 50 for a wide variety of retractorshapes dramatically lowers the cost of the illuminated surgicalretractor 10.

The embodiments described herein provide a novel, low cost illuminationassembly 50 attached in a unique location of the illuminated surgicalretractor 10 which eliminates the expensive electrical and/or opticalinterconnection between the handle 12 and the blade 11 of previousretractors.

The illumination assembly 50 is attached to the illuminated surgicalretractor 10 in a novel way so as to be compatible with a wideassortment of retractor shapes which can be molded vertically orhorizontally. The chemical capacity of the batteries 62 is sufficientfor only a single use and the illuminated surgical retractor isdiscarded after the single use. The intrinsic low cost of theseembodiments makes the illuminated surgical retractor 10 economicallyattractive, and eliminates the inefficiency and expense of cleaning andre-sterilization. Recent evidence is emerging that procedures forcleaning and sterilization are often flawed in practice, resulting inpossible cross contamination of patients. The embodiments describedherein completely eliminate the risk of cross contamination by ensuringthat each of the illuminated surgical retractor 10 is only used once.

In one or more embodiments, the blade, the handle and the curved section(referred to herein collectively as “the body”) are integrally molded.In at least one exemplary embodiment, the material of which the body isformed is a strong, rigid, lightweight plastic (e.g., a polymer). Oneexample of a suitable plastic is a glass-fiber reinforced polyarylamidecompound that provides high strength and rigidity, surface gloss, andcreep resistance. An exemplary embodiment uses a 50% glass-fiberreinforced polyarylamide compound, but those skilled in the art willunderstand that other percentages may be used without departing from thespirit and scope of the claimed invention.

Polyarylamides are thermoplastic crystalline polymers of aromaticdiamines and aromatic dicarboxylic anhydrides having good heat, fire,and chemical resistance, property retention at high temperatures,dielectric and mechanical properties, and stiffness but low lightresistance and processability. Those skilled in the art will understandthat other plastics with suitable strength and rigidity also may beused.

In one or more embodiments, the body is made of a plastic (such asglass-fiber reinforced polyarylamide) having properties of at least oneof radiolucence and nonconductivity. As used herein, “radiolucence”means high transparency to radiation, so that the device may be usedwhen taking, for example, x-ray images. “Nonconductive,” as used herein,means essentially dielectric.

An advantage of radiolucence is that the device may be used when takingX-ray images, without obscuring essential structures, as shown in FIG.9. The “OBP” in FIG. 9 resulted from metal lettering placed below theblades of an embodiment to show the radiolucency. The much darker imageon the left is of a stainless steel comparison blade, which shows up asblack due to its opacity with respect to X-rays.

Embodiments described herein may provide light to the tip of theretractor and still remain highly (as much as 99%) radiolucent. Priorart devices have, for example, fiber optic cables that obstruct the viewwhen X-ray images are taken, even when the devices are constructed ofplastic. Metal devices are, of course, not radiolucent at all.

This radiolucent property means that retractors described herein may notneed to be removed prior to the use of imaging techniques in surgicalprocedures. This can expedite the conduct of a procedure needinganatomic identification and/or device localization.

An advantage of nonconductivity is that it provides improved safety topatients—in contrast to metal retractors. Currents as low as 0.001 A maybe felt by a patient, and larger currents may damage the patient.Embodiments described herein limit currents to less than 10⁻⁶ A, andthus greatly reduce electrical hazards.

For example, electro-cautery is used extensively in surgical tissuedissection. The use of metal retractors exposes the operating surgeonand the patient to the risk of retracted tissue damage due todestructive cautery current being conducted inadvertently. Retractorsare often used to displace and retract delicate cautery sensitivetissues such small or large bowel (colon), lung, or major blood vessels.Cautery injury to these tissues can create major complications. Inaddition, retractors are often used to develop surgical tissue pocketsin breast and pacemaker surgery. Use of a non-electrical conductingmaterial, such as is described herein with respect to certainembodiments, prevents any stray electrical energy injury to theretracted tissues. Patient safety is thus enhanced.

As those skilled in the art will understand, strength is a function ofboth the material and the design. Designs using weaker material than isdescribed herein need to be thicker and more rounded. Both of thesetraits will decrease the favorability of a retractor, which should notblock visibility of the body cavity.

Flexural Strength represents the limit before a material will breakunder stress. Flexural modulus is the tendency of the material to bendunder stress. Both of these parameters are critical to retractor designand resulting performance. First, a retractor blade must be thin enoughto not interfere with the medical procedure for which it is used. Verythick blades will tend to fill the hole in the body that the physicianneeds to work in. An optimal design will have a blade thin enough toallow space for the physician to work. Typically metal blades are usedbecause of their high Flexural modulus. They have unlimited flexuralstrength, because they bend rather than break. Metal blades as thin as0.5-2 mm are readily available and this thickness is small enough to notinterfere with the physician's work space in a wound or operatingcavity. Stainless steel metal can have a flexural modulus of 180 Gpawhich will inhibit blade deformation of more than 10 mm under 15 lbs oftip pressure for most retractor designs.

Plastic injection molded blades require a thicker blade because theyhave a lower Flexural Modulus. Blade strength will increase as the cubeof the blade thickness, but blade thicknesses larger than 2 mm are notdesirable in most physician applications. Typical plastic materials,such as those shown in Table 1 below, have a Flexural Modulus of just afew Gpa and a Flexural Strength of less than 200 Mpa. These lower valueparameters result in retractor blades that deform more than 10 mm underuse, and are likely to break with less than 30 lbs of force placed onthe tip of an average length retractor blade (50-150 mm long).

Retractor blades that deform significantly during use increase thephysician's difficulty in retracting the tissue during a medicalprocedure. Retractor blades that break with less than 30 lbs of forcecan create a hazard to the patient since a broken blade, or pieces of abroken blade, may fall into the patient and create damage. Retractorblades made from the plastics listed in the following table willtypically bend more than 20 mm under 10 lbs of tip force, and will breakat 15 lbs (or even less) of tip force.

TABLE 1 TYPICAL FLEXURAL STRENGTH AND FLEXURAL MODULUS OF POLYMERSFLEXURAL FLEXURAL STRENGTH STRENGTH POLYMER TYPE (MPa) (MPa)Polyamide-lmide 175 5 Polycarbonate 90 2.3 Polyethylene, MDPE 40 0.7Polyethylene 80 1 Terephthalte (PET)

To increase the Flexural modulus and Flexural strength of plastic, in anembodiment, glass fiber is added to the plastic material. FIG. 10 showsa variety of plastics with various percentages of glass fiber added.

It can be seen from the above that the addition of glass fiber canincrease the Flexural Strength of certain plastics to 300 Mpa or above,and increase the Flexural Modulus to 16 Gpa or above. In an exemplaryembodiment, a certain type of plastic, polyacrylamide is infused withglass fiber to create a flexural strength of over 375 Gpa and a Flexuralmodulus of over 17 Gpa.

Plastics with these properties have the ability to create retractorblades of approximately 2 mm thickness that withstand over 30 lbs of tipforce without breaking and deform less than 10 mm under 15 lbs of force.Additionally, the glass fiber in this material will “glassify” at thesurface leaving a very smooth “metal like” finish which is highlydesirable in retractor applications.

The glass fiber in the material also will decrease the likelihood ofsharp shards of material being created during an overstress and breakageevent. This tendency to create dull edges upon breakage decreases thelikelihood that a patient will experience damage if the retractor isoverstressed and ultimately broken.

Additionally, the way in which a material breaks can be important inmedical applications. The breakage characteristics of a material areoften measured by Impact Strength. Materials with low impact strength(10-20 J/M) can break under stress into large numbers of sharp shardswhich can pose a hazard to a patient if material failure occurs during amedical procedure. Sharp shards can cut patient tissue and large numbersof these shards can make it difficult or impossible to remove the brokenmaterial from the patient.

Materials (such as glass fiber reinforced polyarylamide) used in certainembodiments described herein have a high impact strength (>100 J/M) andwill fail with very few fractured component edges (and the resultingedges will be blunt). This breakage characteristic minimizes potentialhazard to a patient during product overstress that results in materialbreakage.

In summary, when compared with the prior art, one or more embodimentsdescribed herein have at least the following advantages:

(1) The non-directional shape of the retaining tab allows theillumination assembly to be utilized with either vertically releasedmolds or horizontally released molds. This use of a common illuminationassembly for a wide variety of retractor shapes dramatically lowers thecost of the illuminated surgical retractor.

(2) The chemical capacity of the batteries is sufficient for only asingle use and the illuminated surgical retractor is discarded after thesingle use. The intrinsic low cost of these embodiments makes theilluminated surgical retractor economically attractive, and eliminatesthe inefficiency and expense of cleaning and re-sterilization. Moreover,using an LED light source as opposed to halogen is advantageous sincehalogen bulbs get very hot and often burn the skin surrounding thesurgical pocket in which a surgeon is working.

(3) The materials used to construct the retractor provide significantsafety and advantages over prior art retractors, including, but notlimited to, at least one of the following: (a) no danger frominsufficient re-sterilization; (b) nonconductivity; (c) radiolucence;(d) high flexural strength and modulus; and (e) high impact strength.

Although the invention has been described in considerable detail hereinwith reference to certain embodiments thereof, other embodiments arepossible. Therefore, the spirit and scope of the appended claims shouldnot be limited to any non-claimed details of the embodiments containedherein.

It will be apparent to the person having ordinary skill in the art thatvarious modifications and variations can be made to the structure of theembodiments described herein without departing from the scope or spiritof the claimed invention. In view of the foregoing, it is intended thatthe claimed inventions cover modifications and variations of theembodiments described herein provided they fall within the scope of thefollowing claims.

I claim:
 1. A surgical retractor, comprising: a blade having a topsurface and a bottom surface; and a handle; a deepened concave portionconnecting a proximal end of the blade to the handle, wherein thedeepened concave portion increases in depth from the proximal end of theblade toward the handle, wherein the blade and the handle are moldedfrom a glass-fiber reinforced polymer having a flexural strength of atleast 300 Mpa; and wherein the blade, being molded from the glass-fiberreinforced polymer, deforms less than 10 mm under 15 lbs of forceapplied thereto.
 2. The surgical retractor of claim 1, wherein thepolymer is a 50 wt % glass-fiber reinforced polymer.
 3. The surgicalretractor of claim 1, wherein the polymer is a thermoplastic crystallinepolymer.
 4. The surgical retractor of claim 3, wherein the polymer is athermoplastic crystalline polymer of aromatic diamines and aromaticdicarboxylic anhydrides.
 5. The surgical retractor of claim 1, whereinthe polymer has a flexural modulus of at least 17 Gpa.
 6. The surgicalretractor of claim 1, wherein the polymer has a flexural strength of atleast 375 Mpa.
 7. The surgical retractor of claim 1, wherein the polymerhas an impact strength of at least 100 J/M.
 8. The surgical retractor ofclaim 1, wherein a proximal tip of the blade withstands over 30 lbs offorce applied thereto.
 9. The surgical retractor of claim 1, wherein thepolymer has a flexural modulus of at least 16 Gpa.
 10. The surgicalretractor of claim 1, wherein the blade has a thickness of 2 mm.
 11. Asurgical retractor, comprising: a blade having a top surface and abottom surface; and a handle; a deepened concave portion connecting aproximal end of the blade to the handle, wherein the deepened concaveportion increases in depth from the proximal end of the blade toward thehandle, wherein the blade and the handle are molded from a polymer, saidpolymer being a low conductivity polymer and a radiolucent polymer;wherein said polymer has a flexural strength of at least 300 Mpa; andwherein the blade, being molded from the polymer, deforms less than 10mm under 15 lbs of force applied thereto.
 12. The surgical retractor ofclaim 11, wherein the polymer has a flexural modulus of at least 16 Gpa.13. The surgical retractor of claim 11, wherein the polymer is a 50 wt %glass-fiber reinforced polymer.
 14. The surgical retractor of claim 11,wherein the polymer is a polyarylamide compound.
 15. The surgicalretractor of claim 11, wherein the polymer is a thermoplasticcrystalline polymer.
 16. The surgical retractor of claim 15, wherein thepolymer is a thermoplastic crystalline polymer of aromatic diamines andaromatic dicarboxylic anhydrides.
 17. The surgical retractor of claim11, wherein the polymer comprises a non-conductive material that limitscurrents to less than 10′ A.
 18. The surgical retractor of claim 11,wherein the blade has a thickness of 2 mm.
 19. A surgical retractor,comprising: a blade having a top surface and a bottom surface; and ahandle; a deepened concave portion connecting a proximal end of theblade to the handle, wherein the deepened concave portion increases indepth from the proximal end of the blade toward the handle, wherein theblade and the handle are molded from a low conductivity polymer, whereinthe polymer comprises a non-conductive material that limits currents toless than 10⁻⁶ A, and wherein a proximal tip of the blade withstandsover 30 lbs of force applied thereto.
 20. The surgical retractor ofclaim 19, wherein the blade, being molded from the polymer, deforms lessthan 10 mm under 15 lbs of force applied thereto.